Solid-propellant gas generator assemblies and methods

A method of retro-fitting a solid-propellant gas generator system, the method comprising:

• removing a first cartridge assembly from the solid-propellant gas generator system, the first cartridge assembly including a first solid-propellant;
• and
• coupling a second cartridge assembly to the solid-propellant gas generator system, the second cartridge assembly including a second solid-propellant configured to burn faster than the first solid-propellant, wherein:
• the first cartridge assembly includes a first housing defining a first cavity extending from a first end of the first housing to a second end of the first housing,
• the first solid-propellant is disposed in the first cavity of the first housing,
• a first flow of gas from burning the first solid-propellant is configured to flow unobstructed in the first cavity;
• the second cartridge assembly further comprises a bulkhead having an orifice disposed in a second housing of the second cartridge assembly,
• the second cartridge assembly further comprises a propellant cavity defined between a first end of the second housing and the bulkhead and a pressure chamber defined between the bulkhead and a second end of the second housing,
• the orifice of the second cartridge assembly is configured to meter a flow of gas into the pressure chamber of the second cartridge assembly, and
• a pressure in the propellant cavity of the second cartridge assembly and the pressure chamber of the second cartridge assembly equalize over time in response to burning the second solid-propellant.